Aortic and iliac fixation of seven endografts for abdominal-aortic aneurysm repair in an experimental model using human cadaveric aortas.

Abstract

To evaluate the proximal and distal (iliac) fixation of seven self-expanding endografts, used in the endovascular treatment (EVAR) of abdominal-aortic aneurysm (AAA), by measuring the displacement force (DF) necessary to dislocate the devices from their fixation sites. A total of 20 human cadaveric aortas were exposed, left in situ and transected to serve as fixation zones. The Anaconda, EndoFit aorto-uni-iliac, Endurant, Powerlink, Excluder, Talent and Zenith stent grafts were deployed and caudal force was applied at the flow divider, through a force gauge. The DF needed to dislocate each device ≥ 20 mm from the infrarenal neck was recorded before and after moulding-balloon dilatation. Cephalad force was similarly applied to each iliac limb to assess distal fixation before and after moulding-balloon dilatation. Endografts with fixation hooks or barbs displayed a significantly higher DF necessary to dislocate the proximal portion compared with devices with no such fixation modalities (p < 0.001). Balloon dilatation produced a significant increase in DF in both devices with (p < 0.001) or without (p = 0.003) hooks or barbs. Suprarenal support did not enhance proximal fixation (p = 0.90). Balloon dilatation significantly increased the DF necessary to dislodge the iliac limbs (p = 0.007). Devices with fixation hooks displayed higher proximal fixation. Moulding-balloon dilatation increased proximal and distal fixation. Suprarenal support did not affect proximal fixation.